1. Field of the Invention
The present invention uses cord blood and or tissue derived stem cells to prevent, lesson, or delay ischemia or the complications of ischemia, including but not limited to stroke, Myocardial Infarction (MI), aging, diabetes, and critical limb ischemia.
2. Description of the Prior Art
There are many different diseases of the organs that affect the population. Included in those diseases, are ones affecting the heart. Chronic myocardial ischemia is the leading cardiac illness affecting the general population in the Western world. Since the occurrence of angina symptoms or objective physiological manifestations of myocardial ischemia signifies a mismatch between myocardial oxygen demand and the available coronary blood flow. The goal of therapy is to restore this balance. This can be achieved either by attempting to prevent further disease progression through modification of risk factors, or by more aggressive modes of therapy such as reducing the myocardial oxygen demand (i.e. reducing the heart rate, myocardial contractility or blood pressure) by using anti-anginal medications, or by restoring the blood supply by means of mechanical interventions such as percutaneous transluminal angioplasty or its variants, or coronary artery bypass surgery, coronary angioplasty (PTCA) or bypass surgery (CABG).
Many tissues in the body fail to regenerate independently after injury or other environmental stresses, and intervention may be required to restore function to those tissues. Organs including the brain, spinal cord, pancreas, liver, kidney, muscle, and upper and lower gastrointestinal tracts are unable to adequately repair after the onset of certain diseases. Similarly, the intrinsic repair mechanisms of the heart are often inadequate to restore function after a myocardial infarction. Thus, destroyed cardiomyocytes are not effectively replaced. The remaining cardiomyocytes are unable to reconstitute tissue lost to necrosis, and heart function deteriorates over time.
Recent attempts to ameliorate the damage caused by myocardial infarction or other disease processes have been directed to regenerating myocardial tissue by implanting a variety of stem and progenitor cells that can differentiate into cardiac muscle. Adult-derived bone marrow cells have been shown to regenerate cardiomyocytes following an infarction. Similar studies have been directed to other organs of the body.
Stem cells have the capacity, upon division, for both self-renewal and differentiation into progenitors. Thus, dividing stem cells generate both additional primitive stem cells and somewhat more differentiated progenitor cells. In addition to the well-known role of stem cells in the development of blood cells, stem cells also give rise to cells found in other tissues, including but not limited to the brain, spinal cord, pancreas, liver, kidney, muscle, and upper and lower gastrointestinal tracts.
Stem cells have the ability to divide indefinitely, and to specialize into specific types of cells. Due to the regenerative properties of stem cells, they have been considered an untapped resource for potential engineering of tissues and organs. It would be a major advancement in science to provide uses of stem cells with respect to addressing acute and chronic diseases of the organs.
Angiogenesis is a complex process that involves endothelial cell migration and proliferation, extracellular matrix breakdown, attraction of pericytes and macrophages, smooth muscle cell proliferation and migration, formation and “sealing” of new vascular structures, and deposition of new matrix. A number of growth factors, including the fibroblast growth factors (FGF) and vascular endothelial growth factors (VEGF) are integrally involved in the angiogenic response in ischemic conditions and in certain pathological states. The availability of these factors has led to studies, which have demonstrated a therapeutic benefit in various animal models of the treatment of acute and chronic myocardial ischemia. In particular, basic fibroblast growth factor is an attractive candidate as an agent for therapeutic angiogenesis. Besides treating heart disease, these growth factors and stem cells are useful in the treatment of diseases of many other organs of the body.
Currently, stem cells are used to treat damage of an organ, including damage caused by ischemia. However, these treatments fail to prevent and/or lesson the organ damage to begin with. There is a need in the art for a treatment method using stem cells that prevents and/or lessons the damage of the organ by focusing on upstream causes, including ischemia, so that the damage may not even occur.